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Vedolizumab drug levels

Blood Sciences Test



Special instructions

Trough (pre dose) specimen required



Test Price


*NHS referral price for drug levels

Test Usage

Managing inflammatory diseases with biological medicines such as Vedolizumab is challenging. Patients may respond well to treatment initially, only to encounter loss of response further ahead in their treatment pathway. Others may not respond to treatment at all. One approach to potentially improve outcomes for patients on Vedolizumab is to measure trough drug levels. However, drug level testing will only be useful if it actually creates positive outcomes for patients. The challenge lies in optimising when this analysis takes place and how best to interpret the data in making clinical decisions that benefit patients. It is widely accepted that undetectable drug level is associated with poor clinical outcomes.

Vedolizumab Therapeutic Drug Monitoring:

The clinical utility of vedolizumab TDM is currently uncertain.

Post hoc analyses of the Gemini registration trials (1) and real-world data (2-4) demonstrate that higher vedolizumab trough levels during induction correlate with higher clinical and endoscopic outcomes in IBD patients.  Whether lower drug levels exacerbate disease activity, or whether higher disease activity results in lower drug levels, remains uncertain.  Prospective studies are required to demonstrate the impact of vedolizumab dose optimisation based on drug levels.

High BMI and low serum albumin levels are predictive of low vedolizumab levels.

A propensity score-based case-matched analysis of UC patients in the Gemini I trials (5) using patient level data, adjusting for confounding factors affecting drug clearance and serum levels suggest target vedolizumab trough levels of:

  • 37.1 mg/L at week 6
  • 18.4 mg /L at week 14
  • 12.7 mg/L during maintenance treatment.

Although prospective studies are required to demonstrate clinical utility, based on experience of anti-TNF TDM possible uses of vedolizumab TDM include:

Proactive TDM

  • A week 6 drug level might help inform decision as to whether to give a week 10 dose

Reactive (in the setting of treatment failure):

  • vedolizumab drug level <3.0 mg/L AND positive antibodies – suggest stop vedolizumab
  • vedolizumab drug level <12.7 mg/L – suggest increase dose of vedolizumab as higher vedolizumab trough levels during induction correlate with higher clinical and endoscopic outcomes in IBD patients.


  1. Rosario M et al JCC 2017;11:921-9
  2. Williet N et al Clin Gastroenterol Hepatol 2017;15:1750-1757
  3. Dreesen E et al Clin Gastroenterol Hepatol 2018;16:1937-1946
  4. Ungaro R et al JCC 2019
  5. Ostermann MT et al APT 2019;49:408-18


Local test, can be added on to an existing request

Turnaround time

2 weeks


We welcome referrals for Vedolizumab monitoring. If you are a new requestor please complete the following form: New requestor form. 

We now also have the option to use NPEx for referral requesting.

Further information about sample requirements for this test can be found here: Vedolizumab and Anti-Vedolizumab Antibodies – further information

Specimen Labelling Procedure

Specimen Labelling Procedure
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